Ladder

Introduction to C Syntax

Below is a flurry of C syntax (we promise it won't be like this for the future exercises).

At the top of the file we have an include statement to include stdio.h, a library that contains functions such as printf.
Next is an array declaration using the int {name}[{size}] syntax.
- This array declared on the stack. The distinction between declaration on the stack and heap is important to keep in mind!
We can initialize the values by using the {elem1, elem2, ...} initializer syntax.
We can also assign each element individually to initialize the array.
- If we do not assign a value to an element then it takes on garbage data. Be careful!
We have a for loop that iterates over our array
- Note that there is no len function to determine the length of an array, so we typically keep track of the length in a variable.
There's a printf statement that formats a string to be printed out. In this case %d formats the input into a number.
- printf is your friend for debugging!
We can declare a string by using the type char* which is a pointer to the first character of the string
- In this case we use %s inside printf to print out strings

#include <stdio.h>

int main(int argc, char *argv[]) {
    const int NUMS_SIZE = 3;
    // Declare an array on the stack of length 3 in one line
    int nums[NUMS_SIZE] = {1, 2, 5};

    // Alternatively initialize an array like this
    nums[0] = 1;
    nums[1] = 2;
    nums[2] = 5;

    for (int i = 0; i < NUMS_SIZE; i++) {
        // printf doesn't emit a new line so we add a \n
        printf("Num at index %d is %d\n", i, nums[i]);
    }

    // We can declare strings and print them out using %s
    char *str = "abcd";
    printf("My string is %s\n", str);

    // A return value of 0 means there were no errors
    return 0;
}

Output:
Num at index 0 is 1
Num at index 1 is 2
Num at index 2 is 5
My string is abcd